The vaccine RV001 targets RhoC, a small GTPase that is overexpressed in advanced solid tumors.
The FDA has granted Fast Track Designation to RV001, an investigational synthetic long peptide vaccine that targets RhoC, for the treatment to patients with prostate cancer.1
RhoC is a small GTPase that is overexpressed in advanced solid tumors. Results from a phase 1/2 first-in-human study published in the Journal for ImmunoTherapy of Cancer showed that 18 of 21 evaluable patients had an immunological response to RV001.2 Safety data showed that the vaccine was tolerable with no grade ≥3 treatment-related adverse events reported.
"We are extremely pleased and proud that our drug candidate, RV001, has earned Fast Track Designation by the FDA. We obviously appreciate the benefits that this might entail in terms of access to FDA advice and an accelerated approval process. But also the fact that the FDA has reviewed our data, and found our drug candidate worthy of this level of priority, obviously sends a clear signal of recognition of the drug's potential to all our would-be partners, which is something of great importance to us," Anders Månsson, CEO of RhoVac, the manufacturer of RV001, stated in a press release.1
The phase 1/2 study (NCT03199872) included 22 patients aged ≥18 years who had previously received radical prostatectomy. Patients had histologically confirmed adenocarcinoma of the prostate gland and were not receiving anticancer therapy at the time of enrollment. Prior androgen-deprivation therapy was not allowed. Patients had an ECOG performance status of 0 or 1.
RV001 was administered subcutaneously every 2 weeks for 6 injections, then 5 times every 4 weeks for a total treatment regimen duration of 30 weeks. Safety was the primary outcome measure with immunological response as a secondary outcome measure.
Overall, 18 of 21 evaluable patients developed a strong CD4 T cell response against the vaccine. The response durations all lasted at least 10 months after the patient received the last injection of RV001. The investigators identified 3 promiscuously presented HLA-class II epitopes. “Vaccine-specific CD4 T cells were polyfunctional and effector memory T cells that stably expressed PD-1 (CD279) and OX-40 (CD134), but not LAG-3 (CD223),” the study authors explained.2 Additionally, there was 1 detected CD8 T cell response.
“Targeting of RhoC induced a potent and long-lasting T cell immunity in the majority of the patients. The study demonstrates an excellent safety and tolerability profile,” the authors wrote in their study conclusion.2
RV001 is currently being evaluated in the double-blind phase 2 BRaVac trial in men with biochemical failure following curatively intended therapy for localized prostate cancer. Patients enrolled on the trial will be randomized to RV001 or placebo. The primary outcome measure is time to PSA progression and the estimated primary completion date is September 2021.
1. RhoVac's Prostate Cancer Drug Candidate, RV001, is granted Fast Track Designation by the FDA. Posted online November 25, 2020. https://prn.to/3m86J9X. Accessed November 25, 2020.
2. Schuhmacher J, Heidu S, Balchen T, et al. Vaccination against RhoC induces long-lasting immune responses in patients with prostate cancer: results from a phase I/II clinical trial. J Immunother Cancer. 2020;8(2):e001157. doi: 10.1136/jitc-2020-001157
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